It is commonplace for an automobile, truck, and other wheeled vehicle to leave a paved roadway and lose tire traction, resulting in spinning wheels that leave the vehicle immovable under its own power. In cases where the vehicle is relatively light and has multiple occupants, it is often possible for the passengers to push the vehicle a short distance, allowing the wheels to regain traction. However, lone drivers, or those with relatively heavy vehicles, are typically not able to move the vehicle even the short distance that is required to regain traction. Drivers stuck in this predicament have typically been forced to call a tow truck to pull them out, resulting in lost time and, often, significant out of pocket expense. Further, in cases where emergency vehicles, such as ambulances, fire trucks, and police cars, are stuck, the time required for a tow truck to arrive may result in far greater consequences than boredom and lost productivity.
Because of the inability of a tow truck to reach stranded off-road vehicles, it is commonplace for off-road vehicles, such as four-wheel drive pickup trucks, to be equipped with an electric or hydraulic winch. In the event that the vehicle is stuck, the winch wire is secured to a fixed or heavy object, such as a tree or other vehicles, and the winch is wound, effectively pulling the vehicle the required distance. However, because most drivers do not drive off-road and do not have a frequent need for a winch, the vast majority of vehicles are not equipped with a winch. Further, the cost of a winch, and the need to retrofit a vehicle to accept it, effectively precludes the purchase and use of an attachable winch that could be stored in the trunk of a passenger vehicle.
Yet another way to pull a vehicle a short distance is to use a ratcheting mechanical device, often called a “come along”. These devices typically include a metal cable that is secured to a fixed or heavy object, such as a tree or other vehicles, and wound around a hub through the actuation of a lever. When used properly, these devices are sufficient to move a relatively light vehicle the necessary distance and, unlike a winch require no retrofitting and are adapted for storage in the trunk of a passenger vehicle. However, these devices have significant drawbacks. For example, the fact that a come along is hand actuated means that most drivers will not be able to actuate the lever to pull heavy vehicles, and many drivers would be unable to move even the lightest of vehicles. Further, the need for the driver to be located outside of vehicle and proximate to the cable results in a significant risk of personal injury in the event that the device malfunctions or the cable breaks.
Another way to pull a vehicle a short distance is to attach a rope or cable to another vehicle and use the power of that vehicle to pull the stranded vehicle the distance required to regain traction. This method is fairly effective in circumstances where the towing vehicle has excellent traction and sufficient power to pull both vehicles. However, in cases where traction is poor, such as on the snow or ice that often will be the cause of the stranded vehicle leaving the roadway, it is often impossible to generate the force required to propel both the towing vehicle and the stranded vehicle the required distance.
Still another way to pull a vehicle a short distance is described in U.S. Pat. Nos. 1,165,510, 1,526,206, 3,099,416, 3,123,823, and 6,375,110, which each describe variations of wheel operated winch attachments. All of these attachments to vehicle wheels are attached to the stuck vehicle in order to pull them out of the mud or snow, and include a drum or cage or bolted on brackets that mimic a drum. In each, the drums are small relative to the wheel, which creates an inherent mechanical advantage where several rotations of the drum would be equal to one rotation of the wheel with proper traction, providing a mechanical advantage in winding. However, each has distinct drawbacks that make them impractical as towing winches and, hence, ineffective in cases where there is no fixed object upon which to attach the line.
First, when attached to a towing vehicle in the manner described in each patent, the use of the spool creates a mechanical disadvantage; i.e. it takes more torque to pull the stuck vehicle as the distance of line wound onto the winch is added to the distance traveled by the towing vehicle. Second, by towing in this manner, the distance between vehicles is diminishing the further the towed vehicle is pulled, running the risk of a collision. Finally, none of these winches has any torque-limiting means to prevent over-torqueing of the wheels, which can create a significant safety hazard from snapped lines and both safety and damage hazards from the unintended disengagement to the winch from the wheel.
Therefore, there is a need for an apparatus and/or system that will pull a vehicle a relatively short distance, that does not require permanent installation on, or retrofitting of, a vehicle, that is significantly less expensive than winches, that is readily storable in the trunk of a passenger car, that may be quickly and easily mounted to a vehicle, that reduces the risk of personal injury by locating the driver in the vehicle during operation, that may be effectively used by all drivers of heavy or light vehicles, that is readily adapted to provide a mechanical advantage in towing applications, and provides at least one safety mechanism that prevents excessive force from being exerted upon the system.